Phase behaviour properties for a material have varied uses. These properties may be taken into consideration when designing or operating chemical or physical processes involving the material.
One potential use of the phase behaviour properties of a material is in the extraction of hydrocarbons from an underground reservoir. When the phase behaviour properties of a reservoir material disposed within the underground reservoir are better understood, operating the extraction can be made safer, and the recovery of the reservoir material can be optimized. Likewise the phase behaviour properties of any injected fluid, under a range of conditions, are relevant to many oil and gas operations.
Another potential use of the phase behaviour properties of a material is in addressing CO2 emissions. Climate change may be influenced by factors including anthropogenic CO2 emissions. Capture, conversion or storage of CO2 will require safe transport of CO2 via pipelines. Industrial CO2 is often mixed with other compounds. The phase properties of the mixture are dependent on the amounts of each compound present in the mixture. Often, small changes in the composition can have large effects on the phase behavior properties. The determination of the phase behaviour properties of a specific CO2 mixture, or other mixture, can help determine conditions for safe transport in pipelines. If a gaseous mixture comprising CO2 and water vapour were transported in a pipe, it may be desirable to design and operate the transport line at conditions where no liquid phase would form. If water were to condense in the pipe, the reaction with the CO2 may generate corrosive acids. Further, sequestration operations may require that the CO2 is safely stored and disposed of at particular conditions, such as disposal by dissolving it in a saline aquifer. The conditions at which these aquifers are present can affect whether it is safe to dissolve and store the sequestered CO2 in such aquifers.
A major limitation of traditional phase property measurement technologies is that only a single pressure-temperature condition can be measured at one time. The most common configuration is the pressure-volume-temperature (PVT) cell, common in petro-chemical and polymer processing applications. These cells typically vary in size between 100 mL and 1 L, and reach pressures and temperatures of 60 MPa and 150° C., respectively. Since thermal and chemical equilibrium within these large systems must be reached between measurements, obtaining a full map of fluid phase behavior can take months, at considerable expense.
Microfluidic technologies have emerged as a tool for rapid, parallel measurements, leveraging short micro-scale diffusion times. U.S. Pat. No. 8,340,913 describes microfluidic techniques that measure pressure-temperature phase properties within a single microchannel including dew point and bubble point. However, phase mapping within a continuous flow suffers drawbacks such as from poor precision due to multiphase flow instabilities, high-speed imaging limitations, subjective operator assessment, and impurity accumulation at phase change interfaces.
There exists a need for improved methods and apparatuses for determining phase properties of a sample fluid.